Na, I really only have problems with Solar Wind and some of those exploration missions that are heavy on the asteroids. Sometimes the cloud at the sensor array in Cap and Hold gets a bit rough too. Pets on the other hand only bother me because I'm a tab targetter (/facepalm).
turning off the shadows in the graphics-menue gets rid of the performance issues with massed fighters on many machines. And you wont see a real diffrence of the image quality in space.
Already there, I still have issues occasionally. It seems kind of random when the lag kicks in, but when it does it doesn't calm down till long after the swarms are gone. Sometimes 4 carriers with pets plus mines and photonic fleets don't mess me up at all, sometimes they do, and sometimes I'm fine until I fight them for 3 or 4 minutes.
There needs to be a general reduction of potential clutter in PvP. If that means halving the number of NPC ships and mines while doubling their power I'd be fine with it. The shear numbers cause some metagame problems.
Not the best test case, but I saw no lag with a 5 man carrier group last night, at the height of the battle when we each had 24 fighters deployed, a fed was dropping mines and clusters everywhere, at least 4 photonic fleets were present, 3 or 4 support fleets, TCDs going everywhere, a nebula spaming his tach grid, and three fed cruisers dragging green goo everywhere... no lag on my end...
The fed escort was lagging though, he was teleporting around and *****ing up a storm over it because he would line up start to fire then lagaport to the other side of his target where he is prompted punished for his attempted shield/hull alpha of doom attempt by the swarms of angry klingon's flying the second most fragile ship in game...
THe worst thing I've seen, is being in a zone like Ker'rat, and actually haveing Borg sneak up on me because the maximium number of objects are on screen for me and then something will die and "Oh look, there's a borg Cube 5km from me.."